Assessment of DES Models for Separated Flow From a Hump in a Turbulent Boundary Layer

Turbulent flow past the Glauert-Goldschmied body, a flow-control hump in a turbulent boundary layer, is studied numerically using detached-eddy simulation (DES), zonal detached-eddy simulation (ZDES), delayed detached-eddy simulation (DDES), and Reynolds-Averaged Navier-Stokes (RANS) modeling. The geometry is smooth so the downstream separation point is not set by facets of the geometry but is a function of the pressure gradient, a challenging condition for turbulence models. Comparisons to experimental data show that RANS with the Spalart-Allmaras turbulence model predicts the mean-field statistics well. The ZDES and DDES methods perform better than the DES formulation and are comparable to RANS in most statistics. An analysis of model behavior indicates that modeled stress depletion in the detached shear layer shortly after separation leads to loss of accuracy in the DES variants.